Yin Metal Snake (Xin Si, 辛巳) day pillar
A Yin Metal day master, the Jewel, sitting on the Snake.
Your day pillar is the pair of characters for the day you were born. The top one, the stem, is your day master — you. The bottom one, the branch, is what it sits on. The sixty pillars come round in turn, one a day, so about one person in sixty was born on a Xin Si day.
Its sound element: White Wax Metal (Bai La Jin, 白蜡金)
The sixty pillars go in pairs, and each pair carries a sound element (Na Yin, 纳音) — an image, separate from the element of the stem. The classic San Ming Tong Hui (三命通会) describes each pillar by it:
Metal hidden away, mixed with sand and stone; likes Fire, and autumn.
金之幽者，杂沙石，喜火及秋
What the Snake holds, and what it is to Yin Metal
Each branch holds one to three stems. The ones under your own day master are the closest things to you in the chart.
- Yang Fire (Bing, 丙), the main one — Direct Officer (Zheng Guan, 正官). What controls you, opposite polarity. Authority in its orderly form: office, rule, the structure you fit into.
- Yang Metal (Geng, 庚) — Rob Wealth (Jie Cai, 劫财). Same element, opposite polarity. A peer who takes rather than shares — the tradition reads it as what draws on your resources through people close to you.
- Yang Earth (Wu, 戊) — Direct Resource (Zheng Yin, 正印). What produces you, opposite polarity. Straightforward support: what teaches, shelters and backs you.
In San Ming Tong Hui’s section on where each stem is born and dies, the Snake is where Yin Metal dies (Si, 死).
A Xin Si day at each birth hour: San Ming Tong Hui (三命通会)
Two volumes of this classic go hour by hour, and at each hour say something about this exact day pillar. These are its sentences on a Xin Si day; what it says about the other five Yin Metal days is on the Yin Metal day master page. Hours are true solar time, not clock time.
Rat hour 23:00–01:00 · Yang Earth Rat (Wu Zi, 戊子)
Tiger (寅), Snake (巳) and Horse (午) months, Direct Officer (正官), conspicuously noble. Pig (亥) and Rat (子), Hurting Officer (伤官), few children and many wives. Rabbit (卯) and Dog (戌), fifth grade, noble. The Shen Bai Jing (神白经) says: the Metal transformed image governs nobility. It dislikes a Fire Tiger (丙寅) month, punishment, level; a Wood Snake (乙巳) month, poor at first; a Fire Rooster (丁酉) month, early death.
Ox hour 01:00–03:00 · Yin Earth Ox (Ji Chou, 己丑)
born in Ox (丑), Snake (巳), Monkey (申) or Rooster (酉) months, the Metal in quantity controls the Wood, damaging and injuring wife and children; as a monk or priest, noble. Tiger (寅), Rabbit (卯) and Dragon (辰) months with a southern period, noble.
Tiger hour 03:00–05:00 · Yang Metal Tiger (Geng Yin, 庚寅)
spring noble; summer, officer and the prosperity star (禄), running a northwestern period, greatly noble; autumn, the self strong; winter, violent and fierce. One account says wealth after punishment.
春贵；夏官禄，行西北运，大贵；秋身旺；冬暴狠。一云刑后有财。
Rabbit hour 05:00–07:00 · Yin Metal Rabbit (Xin Mao, 辛卯)
spring, the wealth strong; summer, the officer strong; autumn, the self robust; winter, weak and yielding. Snake (巳) and Rooster (酉) in year or month running Wood and Fire periods, a noble relation. A Monkey (申) month with Water and Fire periods, gold and purple. A Snake month with a northwestern period, the censorate.
春，财旺；夏、官旺、秋，身强；冬，懦弱。巳酉年月，行木火运，贵戚。申月、水火运，金紫。巳月、西北运，风宪。
Dragon hour 07:00–09:00 · Yang Water Dragon (Ren Chen, 壬辰)
spring, coming to prominence; summer ordinary, with name and profit, and it governs violence and cruelty. A Rooster (酉) month running an eastern period, noble. Dog (戌) and Goat (未), the four vaults complete, most noble. Pure Goat, mixed-qi wealth and Resource (印). Ox (丑) and Goat clashing it open, it governs authority and rank.
Snake hour 09:00–11:00 · Yin Water Snake (Gui Si, 癸巳)
transforming to nobility. A Rat (子) or Horse (午) year and Tiger (寅), Horse or Dog (戌) months, noble; Pig (亥), Rabbit (卯) and Goat (未), pure and noble. Monkey (申), Rat and Dragon (辰), a person without right feeling. Metal Snake (辛巳) and Water Snake (癸巳), the two stems unmixed with Tiger and Dragon, and Yang Fire (丙) showing — all govern the highest nobility. Ox (丑) and Rooster (酉) in triad, also favourable.
化贵。子午年，寅午戌月，贵，亥卯未，清贵。申子辰，无义之人。辛巳癸巳，两干不杂寅辰，透丙，俱主极贵。丑酉三合，亦吉。
Horse hour 11:00–13:00 · Yang Wood Horse (Jia Wu, 甲午)
middling. Tiger (寅), Horse (午) and Dog (戌), the officer strong, favourable. Monkey (申), Rat (子) and Dragon (辰), ordinary. A Rabbit (卯) or Dog year, officer and Resource (印) both complete, duke or marquis.
平。寅午戌，官旺，吉。申子辰、平常。卯戌年，官印双全，公候。
Goat hour 13:00–15:00 · Yin Wood Goat (Yi Wei, 乙未)
where the month carries Metal and Fire, noble. A period running through is also noble.
月通金火，贵。运通，亦贵。
Monkey hour 15:00–17:00 · Yang Fire Monkey (Bing Shen, 丙申)
seeing blood, then blessing; and another account says loss in the midst of nobility. Monkey (申) and Goat (未) in year or month, the self thick, the wife taken twice and the children filial, a military office of the third grade.
见血则福；又云贵中失。申未年月，身厚，妻重子孝，武职三品。
Rooster hour 17:00–19:00 · Yin Fire Rooster (Ding You, 丁酉)
middling. A Pig (亥) month, reversals and unsettled. A Horse (午) month, Seven Killings (偏官) carrying illness, coming to prominence with a short life. A Rat (子) month, a noble relation. One account says there is wealth and there is gladness, and the years do not pass thirty-one.
平。亥月，反复不定。午月，偏官带疾，显达寿促。子月，贵戚。一云有财有喜，寿不过三十一。
Dog hour 19:00–21:00 · Yang Earth Dog (Wu Xu, 戊戌)
Dragon (辰), Dog (戌), Ox (丑) and Goat (未) months, Direct Resource (印绶), literary nobility with little illness; born in the division where Earth (土) is thick, noble. A Dog month running Wood and Fire periods, the censorate.
辰戌丑未月，印绶，文贵少病；生土厚分野，贵。戌月，行木火运，风宪。
Pig hour 21:00–23:00 · Yin Earth Pig (Ji Hai, 己亥)
the Snake (巳) character filling it in solid, it does not enter the flying to heaven (飞天) pattern and is read as officer and Resource (印) — it governs the parents exhausting their strength to support him, and wealth and rank after.
填实巳字，不入飞天格，作官印论，主父母竭力扶持而后富贵。
Named days in Yuan Hai Zi Ping (渊海子平)
These are decided by the day pillar alone, so everyone born on a Xin Si day is in them. The work attaches conditions to most of them; the passage is given whole.
The ten unpardonable days
The day pillar is one of the ten whose prosperity star (禄) falls in its own decade's Void (空亡). The passage is explicit that it is not simply bad — 况犯者未必皆凶，若内有吉神相扶，贵气相辅，当为吉论 — so it is reported and not graded.
六甲旬中十个日值禄人空亡，如甲辰、乙巳，甲以寅为禄，乙以卯为禄，甲辰旬以寅卯为空亡……余如丙申、丁亥、庚辰、戊戌、癸亥、辛巳、乙丑等日皆仿此。命中犯者，当以日上见之为是，其余不论
The Snake and the other animals
When the day branch meets these — in a year, a ten-year luck period, or someone else’s chart — the classics read it by these relationships.
- Clashes with
- Pig
- Pairs with (six harmony)
- Monkey
- In a trine with
- Ox, Rooster
- Punishment with
- Tiger, Monkey
- Harms
- Tiger
- Breaks
- Monkey
The next Xin Si days: 3 November 2026, 2 January 2027, 3 March 2027. It returns every sixty days.
Famous people born on a Xin Si day
- Yoichiro Nambu Physicist · Nobel Prize in Physics, 2008
The Yin Metal day master · Before it: Geng Chen · After it: Ren Wu · All sixty day pillars